Domestic science (Clark, Cornell home economics)

Nitrogenous and Carbohydrate principles are the two most important in cookery. Starch represents the carbohydrates; so for the further study of starch and its digestion we will take up a lesson on cornstarch. The outer covering of plants is called cellulose and within the cellulose is the starch, often called a carbohydrate — a compound that is contained in all plants. As the practice work in this lesson is quite short, the pupils may take this lesson as a study of digestion of starch. Have all the reading language and geography work for the week center around this subject. Take up subject of Digestion of Starch, and write a composition this week on the subject. Pupils bring in all information possible in regard to starch, from chemistries and books of reference, and all sorts of information from books in the Public Library. Information secured in this way is much more valuable than that given entirely by the teachers, as it leads to pupils forming the excellent habit of finding information for themselves, thus getting into touch with leading and authentic authorities on various subjects. This general plan of gathering notes on food stuffs should be followed in all the lessons. Pupils should bring in samples of food stuffs procured from wholesale and retail grocers, for each new lesson. Cornstarch is another starchy food, made from ground Indian corn. The ground corn is then treated with a chemical compound which removes the oil, mineral and proteids; then a powder is produced, called cornstarch. This is nearly pure starch. Arrowroot is the purest form of starch and comes from the West Indies. Tapioca comes from the roots of a plant that grows in South America. Starch may be used as a thickening agent. Cold water has no effect on it. Hot water hardens it in lumps. Experiments, a. Hot water on a cold-water mixture makes a smooth paste. b. Boiling water on sugar and flour mixture makes a smooth product. c. Flour and very hot fat form a soluble mixture, dextrine, which is dissolved in Uquids, forming a smooth product like gelatine. These mixtures may be used in cooking for: a. CORNSTARCH MOULD 25 thickening soups, gravies, sauces; b, for puddings, cream pies, pudding sauces. Cornstarch Moulds — Home Recipe. 1 qt. milk, 4 tbsp. cornstarch, 4 tbsp. sugar, J tsp. salt, 1 tsp. vanilla. School Recipe. 4 tbsp. milk, 1 tsp. sugar, spk. of salt, 1 tsp. cornstarch, spk. vanilla. Method. Mix cornstarch with 1 tbsp. milk. Heat rest of milk in double boiler; add sugar and salt to milk. When the milk is hot, or has a scum on it, add mixture of cornstarch and cold milk; or, heat all milk in double boiler, mix sugar, cornstarch and salt, and add to hot milk. Stir until smooth and cook until thick. Place in a wet mould and set aside to cool. Experiments for Testing Starch. If you have a microscope, cut a thin slice of a raw potato to show cells containing starch. If you have no microscope, hold thin slices of potato toward the light to see the structure, and put drawings in your book showing this structure. Composition. Small test-tubes can be purchased at any drug store. Place some dry starch in a testtube and heat. See the change in color, the odor, the moisture on the sides of the tube. Near the end of the experiment light a match and apply to the mouth of the test-tube to ignite the combustible gases which are given off. You may then break the tube and look at the contents. If any nitrogen had been present the odor would have been like burnt feathers. Action of Cold Water on Starch. Take ^ tsp. cornstarch and add 2J tsp. cold water. Mix this thoroughly. Let it stand in cold water imtil it settles. When the water is clear, drain it off and dry the starch.